1. Field of the Invention
The invention relates to a system of electronic musical instruments such as an electronic keyboard instrument, an electronic drum apparatus, a rhythm apparatus, an automatically performing apparatus, an automatically accompanying apparatus, or the like. In particular, the invention relates to a technology by which sound generating units in such electronic musical instruments are caused in sequence to generate musical tones, as well as to a further technology for processing a succeeding additional "note-on" signal that is input to said electronic musical instruments after the preceding same musical note has been input thereto so that the same musical tones are superposed one on another.
2. Description of Related Art
Each of the musical tone-generating apparatuses that are currently known has only a limited number of, for instance sixteen, tone generators. Accordingly, in such electronic musical instruments of this type, there will occur a shortage of generated musical tones in playing many sounds at the same time while a hold pedal is pressed down. In other words, some tones are not generated, or undesirably decay or die away quickly in such a case.
The so-called musical instrument digital interface (MIDI) is widely employed in electronic musical instruments so as to transmit tone-generating control data between unit apparatuses included therein. The MIDI has therefore given rise to a new system of electronic musical instruments such that a tone data-generating apparatus is coupled with a plurality of tone-generating apparatuses by means of the MIDI. In this case, some additional tone-generating apparatuses can be added to the existing ones and connected by the MIDI to the tone data-generating apparatus in order that a possible insufficiency in the number of sound sources may be complemented.
Also proposed already is another system of electronic musical instruments in which one keyboard apparatus is connected with each of two musical tone-generating apparatuses (A) and (B) by means of the MIDI wherein note signals carrying odd code numbers are selectively received by the apparatus (A) whereas the other note signals carrying even code numbers are selectively received by the other apparatus (B). According to this system, a series of tone control data are divided into two groups that are respectively supplied to the tone-generating apparatuses (A) and (B), resulting in an increase of the numbers of musical tones simultaneously generated at a time because there is no chance that the keyboard apparatus is operated only for the musical notes carrying the odd numbers or only for those carrying the even numbers. These note signals from the tone-generating apparatuses (A) and (B) are processed by a common amplifier and are output through a common loud-speaker.
On the other hand, in another known system, if a succeeding second note-on signal for a musical note is to be fed to a tone-generating apparatus to which a preceding first note-on signal has been fed as the same musical tone in order to superpose these same musical tones one upon another, then the second signal is assigned to a musical tone-generating channel different from the tone-generating channel to which the first tone was assigned.
Subsequent to said processing in the known system, a sound of the tone which is being produced in response to the preceding note-on signal is damped quickly upon initiation of the tone generation corresponding to the assignment of the second note-on signal to the tone-generating channel.